Introduction to the hottest storage graphic interp

Introduction to storage: Graphic explanation of DAS, NAS, San

at present, in the disk storage market, storage classification (as shown in Table 1) is divided into: closed system storage and open system storage according to the type of server. Closed system mainly refers to mainframe, AS400 and other servers, and open system refers to servers based on windows, UNIX, Linux and other operating systems; Open system storage is divided into: built-in storage and external storage; The plug-in storage of open systems is divided into direct attached storage (DAS) and fabric attached storage (FAS) according to the connection mode; Networked storage of open systems is divided into network attached storage (NAS) and storage area network (SAN) according to the transmission protocol. At present, most users use the open system, and it is inappropriate to measure the deflection by using the displacement of the beam outside. The hanging storage accounts for more than 70% of the current disk storage market. Therefore, this paper mainly discusses the hanging storage of the open system. Table 1

today's storage solutions are mainly: Direct Attached Storage (DAS), storage area network (SAN), and network access storage (NAS). Table 2 below:

analysis and comparison of NAS and San

experts have put forward many solutions to the problem that i/o is the bottleneck of the low efficiency of the whole network system. Among them, the most effective way to grasp the crux and have been tested in practice is to separate the data from the general application server to simplify storage management

Figure 1 shows the original problem: each new application server must have its own memory. This leads to complex data processing. With the continuous increase of application servers, the efficiency of the network system will decline sharply

figure 2

it can be seen from Figure 2 that the storage is separated from the application server for centralized management. This is called storage networks

advantages of using storage network:

unity: the form is scattered and the spirit is not scattered, which is logically complete

realize centralized data management, because they are the real lifeblood of the enterprise

is easy to expand, that is, it has strong contractility

with fault-tolerant function, there is no single point of failure in the whole network

experts have adopted two different implementation methods for processing and distribution, namely, NAS (Network Attached Storage) network access storage and San (storage area networks) storage area network

nas: users can calculate, analyze and deal with the consequences of single piece and group experiments, micro print various declaration situations, access data through tcp/ip protocol, and use industry standard file sharing protocols such as NFS, HTTP, CIFS to realize sharing

san: access data through dedicated fibre channel switches, using SCSI and FC-AL interfaces

what are the fundamental differences between NAS and San

the most essential difference between NAS and San is where the file management system is. As shown in the figure:

it can be seen from Figure 3 that in the San structure, the file management system (FS) is still on each application server separately; NAS means that each application server uses the same file management system through network sharing protocols (such as NFS and CIFS). In other words, the difference between NAS and SAN storage system is that NAS has its own file system management

nas focuses on applications, users, files, and the data they share. San is a reliable infrastructure that focuses on disk, tape and their connection. In the future, the comprehensive solution from desktop system to centralized data management to storage devices will be NAS plus San. (end)